Microalgal Proteins

Proteins are the quiet majority inside a microalgal cell. Across the species in commercial culture they account for roughly 23–63% of dry biomass, and in well-run Arthrospira (Spirulina) cultures the share climbs toward 60–70%. What draws formulators to them is not just the quantity. The amino-acid spread is complete, with lysine and leucine levels that hold their own against egg and soy references, and the protein arrives packaged with phycobiliproteins, carotenoids and B-vitamins — a combination no terrestrial crop offers. Cells double in hours, grow on non-arable land and brackish water, and answer to a bioreactor rather than to a harvest calendar.

Eata Marisource supplies that protein in whatever physical state a programme calls for: disrupted whole biomass for laboratory work, washed and dried protein concentrates for feed and material development, isolates refined past 90% protein (N×6.25) for formulation studies, enzyme-cut hydrolysates that serve as organic nitrogen in fermentation and cell culture, and purified phycobiliproteins for fluorescence and colour work. Culture, harvest, extraction and drying all run on our own lines, so a grade can be tuned to your process rather than merely ordered from a list.

From Intact Cell to Free Protein

Every algal protein project meets the same bottleneck first: the wall. Microalgal protein sits in the cytoplasm and organelles behind a rigid polysaccharide envelope, so yield depends on how thoroughly that envelope is opened. We work with bead milling, high-pressure homogenisation, ultrasonication and enzymatic lysis, choosing the route by species — a thin-walled Chlorella strain and a recalcitrant wild isolate do not forgive the same treatment.

Once the cells are open, the classic sequence takes over: alkaline solubilisation lifts the protein into solution, and lowering the pH toward the isoelectric point collapses the surface charge so the protein drops out as a compact curd that washes clean of salts, pigments and soluble carbohydrates. Published work on Arthrospira reports extraction yields near 37% by this route, with the resulting isolate measuring around 90% protein — numbers our own releases are benchmarked against.

Harvest and Recovery at Scale

Dilute culture is the economics problem of algae: the broth that leaves a photobioreactor is mostly water. Disc-stack separation handles primary recovery of fine cells without chemicals, flocculation concentrates very dilute streams ahead of it, and the recovered paste is washed before drying. Heat is kept deliberately mild through concentration and drying, because the same interfacial properties that make these proteins valuable are the first thing harsh processing destroys.

The Protein Families We Supply

Rather than one commodity powder, the portfolio is organised around how the protein will actually be used. Each family ships with the documentation your downstream work needs — certificate of analysis, protein basis, moisture, ash and heavy-metal screening.

Phycobiliproteins: The Light-Harvesting Fraction

Unique to cyanobacteria and red microalgae, phycobiliproteins are the antenna proteins of photosynthesis — disc-shaped trimers of α- and β-subunits that soak up light the chlorophyll misses. C-phycocyanin from Arthrospira gives the intense natural blue that formulation teams reach for when synthetic dyes are off the table; phycoerythrin from red species is prized in fluorescence-based assay work for its high quantum yield.

These are sensitive molecules. Heat, acidity and light all erode both colour and fluorescence, so the proteins leave our facility either freeze-dried or stably buffered, with handling notes written for the bench rather than the warehouse. Side streams from phycocyanin production are not wasted either — the residual biomass still carries roughly half its weight in protein and re-enters the concentrate line, keeping the arithmetic of the whole operation honest.

How the Protein Behaves in a Formula

Functionality, not just content, decides whether an ingredient survives contact with a real product. Microalgal proteins hold their own in tough conditions: several studies note that they keep emulsifying and foaming under conditions — low pH, elevated salt — that push many plant proteins to their limit.

Where These Proteins Are Being Put to Work

Demand is moving faster than the literature, but five directions dominate enquiries. In alt-protein development, extrusion turns concentrates into fibrous structures (below). In aquaculture, microalgal protein is being engineered as a partial fishmeal substitute that brings palatability and polyunsaturated fatty acids along with the amino acids. Fermentation teams buy hydrolysates as renewable organic nitrogen; and the phycocyanin stream feeds a colour market growing on its own schedule.

Choosing the Right Biomass

Species choice does more for project economics than any later processing step, and the trade-offs are rarely obvious from a datasheet. A few notes from the strains we run most often:

• Arthrospira (Spirulina) —the protein ceiling of the industry at 60–70% of dry weight, and the natural home of C-phycocyanin; filamentous, soft-walled, and mercifully easy to disrupt.
• Chlorella vulgaris —fast, robust and forgiving in culture; the thick cell wall demands real disruption energy but rewards it with clean, neutral green protein.
• Nannochloropsis —cultivated primarily for omega-3 lipids, with the protein-rich press cake available as a circular co-stream; strong fit where feed applications and lipid economics meet.
• Tetraselmis —motile green alga with a good amino-acid balance and natural vitamin cofactor content, a familiar face in aquaculture nutrition programmes.
• Dunaliella —halotolerant and grown in high-salinity ponds; better known for β-carotene, but the de-pigmented protein fraction is available for colour-sensitive formulations.

One honest caveat: methionine tends to be the first-limiting amino acid across algal biomasses. Where a complete profile is non-negotiable, we routinely prepare blends with cereal or yeast proteins and verify the result by full amino-acid analysis rather than by calculation.

What Every Batch Is Checked Against

Protein figures only mean something when the method behind them is declared, so every release carries its basis on the certificate. Nitrogen-to-protein conversion, amino-acid composition and structural integrity are measured, not inferred.

Built Around Your Specification

Standard grades exist because somebody once needed them; most of our volume starts as a conversation instead. Tell us the species, the protein target, the molecular-weight window for a hydrolysate, or the colour and salt constraints of your matrix, and the grade is produced against that brief — from kilogram development lots for method fit-up through to bulk supply once the process is frozen. Custom work spans strain selection, disruption and extraction tuning, blending with cereal or yeast proteins, milling and agglomeration for handling behaviour, and packaging from lab packs to full drums. Send us your specification; the faster way to a usable sample is to describe the application, not the catalogue code.

For Research or Industrial Raw Materials, Not For Personal Medical Use!